Electrical circuit and relay therefor



Jan. i4, 1936. F, X, REES www ELECTRICAL CIRCUIT AND RELAY THEREFOR Filed NOV. 27, 1931 Fie. 1. HG2.

INVENTOR l? /y BY 22M/.

Patented Jan. 14, 1936 UNITED STATES PATENT OFFICE ELECTRICAL CIRCUIT AND RELAY THEREFOR Application November 27, 1931, Serial No. 577,538

8 Claims.

This invention relates in general to electrical circuits and relays therefor, and has more particular reference to detecting means for use in connection with signalling circuits and the like as employed in railway practice.

In the case of signalling circuits and the like, it is desirable to immediately detect grounds, in order to prevent failure of signal operation or operation of the signals at improper times with resulting delays to train movements.

With the above and other considerations in mind, it is proposed, in accordance with this invention, to provide a means whereby not only the grounds can immediately be detected, but the particular line wire in which the ground exits can be at once ascertained, and furthermore, even if the ground is intermittent or transient, the detecting means will still operate and retain its indication even after the ground has temporarily ceased to exist. It is also proposed to have the detecting means operate differentially, whereby to make it very sensitive.

More specifically, it is proposed to connect a balanced relay in a signalling line or the like, in such a way that two oppositely wound coils are ordinarily balanced, but become unbalanced on the presence 0I a ground or of unbalanced grounds, to thereby initiate the operation of the relay, and cut in auxiliary operating means, and through an electrical stick arrangement retain the indication of the ground until a manual operation occurs.

Further objects, purposes and characteristic features will appear as the description progresses, reference being made to the accompanying drawing showing, in a wholly diagrammatic manner, and in no manner whatsoever, in a limiting sense, two forms which the invention can assume. In the drawing:-

Fig. l is a diagrammatic view of one form of the invention.

Fig. 2 is a diagrammatic view of the parts in a different operated position from that of Fig. l.

Fig. 3 is a view like Fig. l, but of a modified form.

In Fig. 1 is shown a control line supplied by a battery A, for controlling signals or the like along a railway right of way. Connected across the battery is a relay B which is of the general form shown in the Field application Ser. No. 452,666 filed 5/15/30, which has resulted in Patent Number 1,969,065 but somewhat differently adjusted.

This relay B includes a core C having a central leg l and two outer legs 2 and 3 carrying oppositely connected high resistance coils 21 and 31 respectively, whereby to produce flux, when energized, in each case flowing downwardly and inwardly to the central leg. On the center leg i, is a low resistance coil il, arranged, when 5 energized, to produce flux additive to that due to each of the coils 21 and 31.

As in the Field application, above referred to, relay B has a pivoted armature 4, mechanically biased, as by spring tensioned contacts G, I-I, I lo and J, (operated by the armature) to an intermediate position as shown in Fig. l, whereby it is positioned equi-distantly from the pole shoes of cores 2 and 3. A contact nger 5 is operated, by il, on initial movement of 4 to close its con- 15 tacts. In the Field application 452,666, this contact nger 5 is normally biased to a Contact making position, but in the present case, it is normally positioned out of contact with its fixed points. 20

For indicating the presence of grounds there are employed two lamps 6 and 'l which could, of course, be of any desired character of indicating means, other than lamps, if desired, such as buzzers or the like. 25

Furthermore, contact finger 5 is adjusted to make contact, on movement of armature 4, before armature 4 has operated G or H to open its contact.

The contact finger H is connected, when in 30 its de-energized position, to ground, as indicated.

As shown in Fig. l, the two windings 21 and 31 balance each other so that armature 4 stays in a neutralfposition due to the spring bias of 35 contacts G, H, I and J, with Contact finger 5 adjusted to take a neutral position, and the other contact lingers G etc., in retracted positions, all as shown in Fig. l.

The lamps 6 and 'l are de-energized, due to 40 fingers I and J being retracted.

Referring now to Fig. 2, the various parts are shown in the positions and conditions assumed when a ground occurs, in this case on the positive wire of the control line. The presence of 45 the ground is indicated by the dashed line 8.

On the occurrence of a ground, as on the positive wire, the coil 31 is partially shunted out by a shunt from one side of coil 31, wire 8, ground, contact finger H and back point, con- 50 tact finger G and back point, and wire I0 to the other side of coil 31.

This shunt around the coil 31, disturbs the normal balance, and allows coil 21 to predominate, and` pick up armature 4 and with it rst 55 move contact nger 5 to the right, and then pick up contact fingers J and H.

'Io make the device more sensitive, and thus care for very high resistance grounds, and for grounds on both wires that are only slightly unbalanced, the contact 5, which closes on the initial movement of armature Il, energizes coil l1 through a circuit obvious from the drawing, to quickly and surely exaggerate the unbalance and continue movement of armature 4 to full picked-up position.

With contact finger 5 swung to the right and contact nger I-I attracted, the partial orrhigh resistance shunt around coil 31 is removed and the balance between coils 21 and 31 isv restored,-

but now coil l1 is energized with twice the voltage of either coils 21 or 31, and armature 4 has been moved toward core 2, so that armature 4 is moved quickly and surely to a position against core 2.

Relay B is thus stuck in the position of Fig. 2, through the front point of contact 5, until the energizing circuit is opened, as by hand switch ll.

With contact nger J in attracted position an energizing circuit for lamp` l is closed as is obvious from the drawing to thus indicate that a ground has occurred and that the ground occurred on the negative wire of the control line.

For a negative ground, instead of a positive ground, the operation is substantially the sameexcept that coil 21 is shunted out and lamp 6 is energized.

The relay can be adjusted to operate directly on any desired voltage and when the battery voltage is higher than that for which it is adjusted it will be necessary to use limiting resistance to reduce the voltage to the desired figure.

It has been found in practice that a system of this character will unbalance on a ground current of .00075 amperes, or on a diierence in ground currents of .00075 amperes, to thereby indicate the presence of a ground.

Referring now to Fig. 3 in this modified form, there are employed two trip coils l2 and I3 connected in series to ground through the contacts G1 and I-I1, and connected at the other end to a point in wire I4, between windings 311 and 211. These coils l2 and I3 are on the respective core legs 3a and 2a, and are oppositely wound. Normally these trip coils are de-energized, but upon a ground occurring in one of the line wires, current ows through them in a manner to cause the shunted out main coil to be opposed by its trip coil, and the other main coil t0 be aided by its trip coil, whereby to in- 'crease the sensitivity of the ground detector and cause it to be much improved.

For example, in Fig. 3, with a ground on the negative line wire, the uxes produced by the various trip coils, are as indicated by the arrows l5 and i6, thus to weaken the shunted coil 211 and strengthen the other coil 311.

The operation is similar for a ground on the positive line wire.

The resistance of the two coils I2 and i3 is small compared with that oi an accidental ground, and hence their presence in the ground connection does not substantially affect the shunting characteristics of a ground on the coils 211 and 311.

It should be noted that the above described ground detector is not a test apparatus which must be connected and disconnected in order to detect a ground but remains connected at all times so as to detect a ground occurring at any time. Furthermore even a transient ground will cause the apparatus to operate and retain its indication to thereby indicate the possibility of a ground later occurring even though the ground which initiated the system was only momentary. Furthermore the indication is positive and certain due to the initiating ground being removed and an auxiliary operating coil (i1) being cut into service by means of the contact ringer 5,

as described above.

The above rather specific description of one form of the invention, has been given solely by way of illustration, and is not intended, in any manner whatsoever, in a limiting sense. Obviously, this invention can assume many different physical forms, and is susceptible of numerous modifications, and all such forms and modifications, are intended to be included by this application, as come within the scope or" the appended claims.

Having described my invention, I now claim:-

l. In detecting means, in combination with a circuit, a single magnetic indicator movable in either of two opposite drections, opposed stabilizing coils connected across the circuit and arranged to exert substantially equal and opposite actions on the indicator, a ground connection to a point between the coils, whereby an unbalanced ground on either side oi the circuit tends to cause movement of the indicator, an operating coil common to the stabilizing coils Yand connected to aid each stabilizing coil, and an energizing circuit for the operating coil closed upon movement of the indicator.

2. In detecting means, in combination with a line, a single pivoted magnetic indicator movable in either of two opposite directions, opposed stabilizing coils connected across the line and arranged to exert substantially equal and opposite.

actions on the indicator, a ground connection to a point between the coils whereby unbalanced grounds on theline cause movement o f the indicator, a trip coil magnetically associated with Veach stabilizing coil and connected in series in the said ground connection, the trip coils being so connected as to each respectively, oppose and aid its stabilizing coil, and vice versa, according to polarity of ground currents therein.

3. In detecting means, the combination with a circuit, a magnetic indicator movable in either of two opposite directions, opposed stabilizing coils connected across the circuit and arranged to exert substantially equal and opposite actions on the indicator, a ground connection to a point between the coils, whereby a ground on one side of the circuit causes movement of the indicator, an operating coil common to the stabilizing coils and connected to aid each stabilizing coil, an energizing circuit for the operating coil closed upon movement of the indicator, a trip coil associated in the same magnetic circuit with each *stabilizing coil, connected in series in the said ground connection, and oppositely connected, whereby each to respectively oppose and aid its stabilizing coil, and vice versa, according to the polarity of any ground current therein.

4. In a ground detector, in combination with a line, an armature pivoted for movement in opposite directions, two coils connected in series across the line and positioned to urge the armature in opposite directions, a ground connection to a point between the two coils, a normally closed contact in the ground connection which is opened upon movement of the armature, a biasing coil connected, when energized, to aid each of the said two coils, and an energizing circuit for the biasing coil including a normally open contact operated on movement of the amature to closed position.

5. In a ground detector, in combination with a line, an armature pivoted for movement in opposite directions, two coils connected in series across the line and positioned to urge the armature in opposite directions, a ground connection to a point between the two coils, a normally closed contact in the ground connection opened upon movement of the armature, a biasing coil connected when energized to aid each of the said two coils, and an energizing circuit for the biasing coil including a normally open contact operated on movement of the armature to closed position, the circuit for the biasing coil closing before the ground connection opens.

6. In a ground detector, in combination, an arma-ture pivoted for movement in opposite directions, two coils connected in series and positioned, when energized, to urge the armature in opposite directions, a ground connection to a point between the two coils, a normally closed contact in the ground connection opened upon movement of the armature, a trip winding in the same iiux path with each of the said two coils, and connected in series with each other in the said ground connection, said trip coils being connected oppositely to each other whereby to each respectively aid and oppose its associated coil in accordance with the polarity of any current in said ground connection.

7. In a ground detector, in combination with a line, an armature pivoted for movement in opposite directions, two coils connected in series across the line and positioned to urge the armature in opposite directions, a ground connection to a point between the two coils, a normally closed contact in the ground connection opened upon movement of the armature, a biasing coil connected when energized to aid each of the said two coils, an energizing circuit for the biasing coil including a normally `open contact operated on movement of the armature to closed position, a trip winding in the same iiuX path with each of the said two coils and connected in series with each other in the said ground connection, said trip coils being connected oppositely to each other whereby to each respectively aid and oppose its associated coil in accordance with the polarity of any current in said ground connection.

8. In a ground detector, in combination with a line, an armature pivoted for movement in opposite directions, two coils connected in series across the line and positioned to urge the armature in opposite directions, a ground connection to a point between the two coils, a normally closed contact in the ground connection which is opened upon movement of the armature, a biasing coil connected when energized to aid each of the said two coils, an energizing circuit for the biasing coil including a normally open contact operated on movement of the armature to closed position, the contact for the circuit for the biasing coil being adjusted to close before that for the ground connection opens, a trip coil in the same iiux path with each of the said two coils and connected in series with each other in the said ground connection, said trip coils being connected oppositely to each other whereby to respectively aid and oppose their associated coil in accordance with the polarity of any energy applied to said ground connection.

FRANK X. REES. 

